Re: [PATCH v2 02/11] soc: tegra: Add Tegra PMC clock registrations into PMC driver

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 12/4/19 12:28 PM, Dmitry Osipenko wrote:
04.12.2019 23:08, Sowjanya Komatineni пишет:
On 12/4/19 8:02 AM, Sowjanya Komatineni wrote:
On 12/4/19 5:39 AM, Dmitry Osipenko wrote:
03.12.2019 19:45, Sowjanya Komatineni пишет:
On 12/2/19 4:07 PM, Sowjanya Komatineni wrote:
On 12/2/19 3:14 PM, Sowjanya Komatineni wrote:
On 12/2/19 3:10 PM, Sowjanya Komatineni wrote:
On 12/2/19 2:58 PM, Sowjanya Komatineni wrote:
On 12/2/19 1:50 PM, Dmitry Osipenko wrote:
02.12.2019 23:09, Sowjanya Komatineni пишет:
On 11/28/19 5:25 AM, Dmitry Osipenko wrote:
28.11.2019 01:57, Sowjanya Komatineni пишет:
On 11/27/19 7:14 AM, Dmitry Osipenko wrote:
27.11.2019 07:59, Sowjanya Komatineni пишет:
Tegra210 and prior Tegra PMC has clk_out_1, clk_out_2,
clk_out_3 with
mux and gate for each of these clocks.

Currently these PMC clocks are registered by Tegra clock
driver using
clk_register_mux and clk_register_gate by passing PMC base
address
and register offsets and PMC programming for these clocks
happens
through direct PMC access by the clock driver.

With this, when PMC is in secure mode any direct PMC access
from the
non-secure world does not go through and these clocks will
not be
functional.

This patch adds these clocks registration with PMC as a clock
provider
for these clocks. clk_ops callback implementations for these
clocks
uses tegra_pmc_readl and tegra_pmc_writel which supports PMC
programming
in secure mode and non-secure mode.

Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
---
      drivers/soc/tegra/pmc.c | 330
++++++++++++++++++++++++++++++++++++++++++++++++
      1 file changed, 330 insertions(+)

diff --git a/drivers/soc/tegra/pmc.c
b/drivers/soc/tegra/pmc.c
index ea0e11a09c12..a353f6d0a832 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -13,6 +13,9 @@
        #include <linux/arm-smccc.h>
      #include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/clk-conf.h>
      #include <linux/clk/tegra.h>
      #include <linux/debugfs.h>
      #include <linux/delay.h>
@@ -48,6 +51,7 @@
      #include <dt-bindings/pinctrl/pinctrl-tegra-io-pad.h>
      #include <dt-bindings/gpio/tegra186-gpio.h>
      #include <dt-bindings/gpio/tegra194-gpio.h>
+#include <dt-bindings/soc/tegra-pmc.h>
        #define PMC_CNTRL            0x0
      #define  PMC_CNTRL_INTR_POLARITY BIT(17) /* inverts INTR
polarity */
@@ -100,6 +104,7 @@
      #define PMC_WAKE2_STATUS        0x168
      #define PMC_SW_WAKE2_STATUS 0x16c
      +#define PMC_CLK_OUT_CNTRL 0x1a8
      #define PMC_SENSOR_CTRL 0x1b0
      #define PMC_SENSOR_CTRL_SCRATCH_WRITE BIT(2)
      #define  PMC_SENSOR_CTRL_ENABLE_RST BIT(1)
@@ -155,6 +160,91 @@
      #define  TEGRA_SMC_PMC_READ    0xaa
      #define  TEGRA_SMC_PMC_WRITE    0xbb
      +struct pmc_clk_mux {
+    struct clk_hw    hw;
+    unsigned long    offs;
+    u32        mask;
+    u32        shift;
+};
+
+#define to_pmc_clk_mux(_hw) container_of(_hw, struct
pmc_clk_mux, hw)
+
+struct pmc_clk_gate {
+    struct clk_hw    hw;
+    unsigned long    offs;
+    u32        shift;
+};
+
+#define to_pmc_clk_gate(_hw) container_of(_hw, struct
pmc_clk_gate, hw)
+
+struct pmc_clk_init_data {
+    char *mux_name;
+    char *gate_name;
+    const char **parents;
+    int num_parents;
+    int mux_id;
+    int gate_id;
+    char *dev_name;
+    u8 mux_shift;
+    u8 gate_shift;
+    u8 init_parent_index;
+    int init_state;
+};
+
+static const char *clk_out1_parents[] = { "clk_m",
"clk_m_div2",
+    "clk_m_div4", "extern1",
+};
+
+static const char *clk_out2_parents[] = { "clk_m",
"clk_m_div2",
+    "clk_m_div4", "extern2",
+};
+
+static const char *clk_out3_parents[] = { "clk_m",
"clk_m_div2",
+    "clk_m_div4", "extern3",
+};
+
+static struct pmc_clk_init_data tegra_pmc_clks_data[] = {
+    {
+        .mux_name = "clk_out_1_mux",
+        .gate_name = "clk_out_1",
+        .parents = clk_out1_parents,
+        .num_parents = ARRAY_SIZE(clk_out1_parents),
+        .mux_id = TEGRA_PMC_CLK_OUT_1_MUX,
+        .gate_id = TEGRA_PMC_CLK_OUT_1,
+        .dev_name = "extern1",
+        .mux_shift = 6,
+        .gate_shift = 2,
+        .init_parent_index = 3,
+        .init_state = 1,
+    },
+    {
+        .mux_name = "clk_out_2_mux",
+        .gate_name = "clk_out_2",
+        .parents = clk_out2_parents,
+        .num_parents = ARRAY_SIZE(clk_out2_parents),
+        .mux_id = TEGRA_PMC_CLK_OUT_2_MUX,
+        .gate_id = TEGRA_PMC_CLK_OUT_2,
+        .dev_name = "extern2",
+        .mux_shift = 14,
+        .gate_shift = 10,
+        .init_parent_index = 0,
+        .init_state = 0,
+    },
+    {
+        .mux_name = "clk_out_3_mux",
+        .gate_name = "clk_out_3",
+        .parents = clk_out3_parents,
+        .num_parents = ARRAY_SIZE(clk_out3_parents),
+        .mux_id = TEGRA_PMC_CLK_OUT_3_MUX,
+        .gate_id = TEGRA_PMC_CLK_OUT_3,
+        .dev_name = "extern3",
+        .mux_shift = 22,
+        .gate_shift = 18,
+        .init_parent_index = 0,
+        .init_state = 0,
+    },
+};
+
      struct tegra_powergate {
          struct generic_pm_domain genpd;
          struct tegra_pmc *pmc;
@@ -254,6 +344,9 @@ struct tegra_pmc_soc {
           */
          const struct tegra_wake_event *wake_events;
          unsigned int num_wake_events;
+
+    struct pmc_clk_init_data *pmc_clks_data;
+    unsigned int num_pmc_clks;
      };
        static const char * const tegra186_reset_sources[] = {
@@ -2163,6 +2256,228 @@ static int
tegra_pmc_clk_notify_cb(struct
notifier_block *nb,
          return NOTIFY_OK;
      }
      +static void pmc_clk_fence_udelay(u32 offset)
+{
+    tegra_pmc_readl(pmc, offset);
+    /* pmc clk propagation delay 2 us */
+    udelay(2);
+}
+
+static u8 pmc_clk_mux_get_parent(struct clk_hw *hw)
+{
+    struct pmc_clk_mux *mux = to_pmc_clk_mux(hw);
+    int num_parents = clk_hw_get_num_parents(hw);
+    u32 val;
+
+    val = tegra_pmc_readl(pmc, mux->offs) >> mux->shift;
+    val &= mux->mask;
+
+    if (val >= num_parents)
+        return -EINVAL;
+
+    return val;
+}
+
+static int pmc_clk_mux_set_parent(struct clk_hw *hw, u8
index)
+{
+    struct pmc_clk_mux *mux = to_pmc_clk_mux(hw);
+    u32 val;
+
+    val = tegra_pmc_readl(pmc, mux->offs);
+    val &= ~(mux->mask << mux->shift);
+    val |= index << mux->shift;
+    tegra_pmc_writel(pmc, val, mux->offs);
+    pmc_clk_fence_udelay(mux->offs);
+
+    return 0;
+}
+
+static const struct clk_ops pmc_clk_mux_ops = {
+    .get_parent = pmc_clk_mux_get_parent,
+    .set_parent = pmc_clk_mux_set_parent,
+    .determine_rate = __clk_mux_determine_rate,
+};
+
+static struct clk *
+tegra_pmc_clk_mux_register(const char *name, const char *
const
*parent_names,
+               int num_parents, unsigned long flags,
+               unsigned long offset, u32 shift, u32 mask)
+{
+    struct clk_init_data init;
+    struct pmc_clk_mux *mux;
+
+    mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+    if (!mux)
+        return ERR_PTR(-ENOMEM);
+
+    init.name = name;
+    init.ops = &pmc_clk_mux_ops;
+    init.parent_names = parent_names;
+    init.num_parents = num_parents;
+    init.flags = flags;
+
+    mux->hw.init = &init;
+    mux->offs = offset;
+    mux->mask = mask;
+    mux->shift = shift;
+
+    return clk_register(NULL, &mux->hw);
+}
+
+static int pmc_clk_is_enabled(struct clk_hw *hw)
+{
+    struct pmc_clk_gate *gate = to_pmc_clk_gate(hw);
+
+    return tegra_pmc_readl(pmc, gate->offs) &
BIT(gate->shift) ? 1
: 0;
+}
+
+static void pmc_clk_set_state(struct clk_hw *hw, int state)
+{
+    struct pmc_clk_gate *gate = to_pmc_clk_gate(hw);
+    u32 val;
+
+    val = tegra_pmc_readl(pmc, gate->offs);
+    val = state ? (val | BIT(gate->shift)) : (val &
~BIT(gate->shift));
+    tegra_pmc_writel(pmc, val, gate->offs);
+    pmc_clk_fence_udelay(gate->offs);
+}
+
+static int pmc_clk_enable(struct clk_hw *hw)
+{
+    pmc_clk_set_state(hw, 1);
+
+    return 0;
+}
+
+static void pmc_clk_disable(struct clk_hw *hw)
+{
+    pmc_clk_set_state(hw, 0);
+}
+
+static const struct clk_ops pmc_clk_gate_ops = {
+    .is_enabled = pmc_clk_is_enabled,
+    .enable = pmc_clk_enable,
+    .disable = pmc_clk_disable,
+};
+
+static struct clk *
+tegra_pmc_clk_gate_register(const char *name, const char
*parent_name,
+                unsigned long flags, unsigned long offset,
+                u32 shift)
+{
+    struct clk_init_data init;
+    struct pmc_clk_gate *gate;
+
+    gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+    if (!gate)
+        return ERR_PTR(-ENOMEM);
+
+    init.name = name;
+    init.ops = &pmc_clk_gate_ops;
+    init.parent_names = &parent_name;
+    init.num_parents = 1;
+    init.flags = flags;
+
+    gate->hw.init = &init;
+    gate->offs = offset;
+    gate->shift = shift;
+
+    return clk_register(NULL, &gate->hw);
+}
+
+static void tegra_pmc_clock_register(struct tegra_pmc *pmc,
+                     struct device_node *np)
+{
+    struct clk *clkmux, *clk, *parent;
+    struct clk_onecell_data *clk_data;
+    unsigned int num_clks;
+    int i, ret;
+
+    /* each pmc clock output has a mux and a gate */
+    num_clks = pmc->soc->num_pmc_clks * 2;
+
+    if (!num_clks)
+        return;
+
+    clk_data = kmalloc(sizeof(*clk_data), GFP_KERNEL);
+    if (!clk_data)
+        return;
+
+    clk_data->clks = kcalloc(TEGRA_PMC_CLK_MAX,
sizeof(*clk_data->clks),
+                 GFP_KERNEL);
+    if (!clk_data->clks)
+        goto free_clkdata;
+
+    clk_data->clk_num = num_clks;
+
+    for (i = 0; i < pmc->soc->num_pmc_clks; i++) {
+        struct pmc_clk_init_data *data;
+
+        data = pmc->soc->pmc_clks_data + i;
+
+        clkmux = tegra_pmc_clk_mux_register(data->mux_name,
+ data->parents,
+ data->num_parents,
+ CLK_SET_RATE_NO_REPARENT |
+ CLK_SET_RATE_PARENT,
+ PMC_CLK_OUT_CNTRL,
+ data->mux_shift, 3);
+        if (IS_ERR(clkmux))
+            goto free_clks;
+
+ clk_data->clks[data->mux_id] = clkmux;
+
+        clk = tegra_pmc_clk_gate_register(data->gate_name,
+ data->mux_name,
+ CLK_SET_RATE_PARENT,
+ PMC_CLK_OUT_CNTRL,
+ data->gate_shift);
+        if (IS_ERR(clk))
+            goto free_clks;
+
+ clk_data->clks[data->gate_id] = clk;
+
+        ret = clk_set_parent(clk, clkmux);
+        if (ret < 0) {
+            pr_err("failed to set parent of %s to %s\n",
+                   __func__, __clk_get_name(clk),
+ __clk_get_name(clkmux));
+        }
+
+        clk_register_clkdev(clk, data->dev_name,
data->gate_name);
+
+        /* configure initial clock parent and state */
+        parent = clk_get_sys(data->gate_name,
+ data->parents[data->init_parent_index]);
Couldn't the default parent be defined using "assigned clock" in a
device-tree? Please see "Assigned clock parents and rates" in the
doc.

https://www.kernel.org/doc/Documentation/devicetree/bindings/clock/clock-bindings.txt



Then you could simply use of_clk_set_defaults(pmc->dev->of_node,
true).
Yes, of_clk_add_provider() does of_clk_set_defaults which sets
based on assigned parents and clock rates.

This need device tree to specify assigned clock parent properties.
Will update device tree and remove init parent from the driver.

assigned-clock properties should be set in consumer node of these
clocks and currently these clocks are not used yet.

So will just remove init parent from driver and when these clocks
are used device tree can be updated in corresponding consumer node
with these properties.

How about default ON/OFF init state for the clocks? I see
assigned-clock properties for parent and rate only.

But based on existing clock-tegra-pmc driver, I see clk_out_1 is
default enabled with extern1 parent for T30 thru T210 platforms.

Peter/Thierry, What was the reason we enable clk_out_1 right from the
clock registration?

clk_out_1 is for audio and its not required to be enabled during the
boot and audio driver can enable/disable it.

same with blink 32khz which is used for WIFI. WIFI driver can
enable/disable during power up/down sequence and technically as per
design we dont need to have it always on right from the boot.

So can remove out clocks init states from driver once thierry also
agree on this.

Hi Dmitry,

Looking at audio driver, it doesn't take care of mclk which is from
clk_out_1 and expects mclk to be always on.

So probably we should have this init state enables in pmc driver for
32Khz and clk_out's to not break existing functionality.
Hello Sowjanya,

IIUC, it's a bug in the device-trees and sound's MCLK actually should be
set to CLK_OUT_1 of PMC instead of CaR's EXTPERIPH1. If that's the case,
then the device-trees need to be fixed.
OK, will have this in v3
Actually if we change mclk to use clk_out_1, then it will break with old
device trees.

Currently clk_out_1 parent is set to extern1 as init state by the clock
driver and device tree for sound node is using extern1 as mclk works and
extern1 itself has enable and disable. But yes implementation wise, its
incorrect as mclk should really be clk_out_1.

Now, with moving clk_out_1 to tegra PMC, pmc is the clock provider and
if we now change the device tree to use CLK_OUT_1 as mclk then it will
break old device tree.
There souldn't be any problem with enabling CLK_OUT_1 by the audio
driver itself (in the code) if an old device-tree is detected.

	clk_out_1 = clk_get(dev, "clk_out_1");
	clk_set_parent(clk_out_1, clk_extern1);
	...
	data->clk_cdev1 = clk_out_1;

Maybe it will be even better to compare clocks for detection of an older DT:

	if (tegra_get_chip_id() > TEGRA20 &&
	    clk_is_match(data->clk_cdev1, clk_extern1)) {
	...

we can do parent init in audio driver which is not an issue.

But I was saying we can keep extern1 as mclk in device tree instead of changing to clk_out_1 from pmc as it will break old device tree becasue we moved clk_out_1 from clock driver to pmc driver.

once we do init parent in audio driver, we still can use extern1 as mclk in device tree.

mclk -> clk_out_1 -> extern1 -> plla_out0 -> plla

with init of clk_out_1 parent to extern1, mclk can use extern1 handle for rate/enable/disable clk operations

Regarding using assigned-clock properties for init parent and removing
init parent from driver, it also needs consumer node in device tree to
be updated to specify assigned-clock properties for default/init
parent.

This breaks device tree ABI as prior Tegra210 supports audio driver.
So it's the sound node which should have had the assigned clocks in
device-tree in order to define route for the audio MCLK clock from CaR
to PMC.

Given that the audio clocks configuration is the same for all of the
currently supported boards, I think it will be better to remove the
entire audio clocks initialization from the clk drivers and move it all
to the audio driver. It could be something like this:

int tegra_asoc_utils_init(struct tegra_asoc_utils_data *data,
               struct device *dev)
{
     ...

     if (!of_find_property(dev->of_node, "assigned-clock-parents",
NULL) &&
         tegra_get_chip_id() > TEGRA20) {
         clk_extern1 = clk_get(dev, "extern1");
         ...
         clk_set_parent(clk_extern1, clk_pll_a_out0);
         ...
         clk_put(data->clk_cdev1);

         data->clk_cdev1 = clk_out_1;
     }
     ...

So now the old device-trees will cointinue to work and new could have
the assigned-clocks and set MCLK to CLK_OUT_1.

[snip]
Will update clk-tegra, pmc and audio driver to move init state
configuration for extern1 and clk_out_1 into audio driver and will use
assigned clock properties in device tree.





[Index of Archives]     [ARM Kernel]     [Linux ARM]     [Linux ARM MSM]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux